1. Field of the Invention
The present invention relates generally to optical fibers, and particularly to bend insensitive optical fibers comprising a low index of refraction glass ring therein.
2. Technical Background
Glass optical fibers with improved bend loss properties have recently been of significant interest in the telecommunications field. Techniques for improving fiber bending properties can play important roles in many types of fibers, including optical fibers used in compact applications, such as for example erbium doped amplifiers and dispersion compensating modules where bending loss has limited many designs from practical use. In certain applications such as fiber to the home applications, the ability to form a tight bending diameter, for example of 50 or 20 mm or less is desired with negligible bending loss. Many of the proposed solutions for this problem involve significant modification of the fiber refractive index profile.